日 本 語

Biomechanics of GroupStudies

Structural formation by cellular automaton model Distributed sensor system Group robots forming a mechanical structure

Please click the research themes for detail descriptions.
(Some parts are in preparation.)

Group of bird or fish or behavior has a leader that determines its behavior of group such as direction of movement. The leader is selected from the group member and is changed to the other member under the environmental condition. Other members only follow neighboring movement, which saves their energy. It is considered that the group system totally becomes a loading state.

On the other hand, our body has multiple muscles to support the form and to work outside. The each muscle cooperatively works so that the total muscular system attains an efficient condition. We call such group systems composed of multiple elements "群" with a Kanji character which means "group".

閉じる
Structural formation by cellular automaton model
The cellular automaton model forming a mechanical structure is learned from remodeling process of living systems. The model consists of many cells mechanically connected with each other. The cell changes its Young's modulus according to a stress value that is produced in the cell. We examined the performance of the model giving each cell local rules. The computer simulation showed that the model formed a framed structure satisfying the boundary condition.


  Aspect ratio =1.0      Aspect ratio=3.0      Aspect ratio=3.0

The each left sides is fixed and a load is applied at the center of the right side as the boundary condition.
The initial distribution of Young's modulus is also affected by structural formation as well as the aspect ratio.

【Literature】
N.Inou, T.Uesugi, K.Todoroki and S.Ujihashi:
Self-Organization of Topological Structures by a Cellular Automaton,
Synthesis in Bio Solid Mechanics, KLUWER ACADEMIC PUBLISHERS, pp.21-32 (1999)
閉じる
Distributed sensor system
Distributed sensor system presents dynamic state of mechanical structures such as buildings or machines, which will greatly contribute to build a damage estimation system or a realtime monitoring system. It needs calibrated precise sensors for building the systems.

# Real-time safety monitoring system for buildings
Safety of a building gradually changes depending on external factors such as aging degradation and vibration by earthquakes. Especially, it is not negligible that structural parts of the building are caused plastic deformations by a large earthquake. For evaluation of the safety, measurement of the deformation is necessary. However, it is not easy to measure the deformation directly because there is no standard position (the ground itself moves!).
This study proposes a monitoring system for buildings by observing multiple points of a building using accelerometers. Deformation, speed, acceleration profiles are measured by accelerometers with integration calculations. For the purpose of realizing this system, accurately calibrated accelerometers are required. This study proposes accurate sensor examination method for 3-axis sensor, in terms of the sensor directions and sensitivity.

【Literature】
Hitoshi Kimura, Masashi Nakamura, Norio Inou, Masayuki Matsudaira,
Minoru Yoshida:
"Identification Method of Sensor Directions and Sensitivities in Multi-Axis Accelerometer (Actual Measurement of Direction Tensor and Sensitivity Tensor)" Journal of Robotics and Mechatronics, Vol.25 No.2, pp.408-416, (2013) 
閉じる
Group robots forming a mechanical structure
Reconfigurable group robots have potential to fulfill various missions such as cooperative transportation, collection and construction. To realize the group robots, variety of mechanisms has been developed. However, there are few robots designed for supporting large external forces. The reason why is that the almost developed robots are putting more emphasis on a mobile function than a supporting function.
Our study focuses on group robots forming a mechanical structure. The group robots consist of cellular robots. Each cellular robot communicates with adjacent robots and determines the behavior where it should be positioned. They form the structure by successive cooperative movements. We call the cellular robot “CHOBIE” (Cooperative Hexahedral Objects for Building with Intelligent Enhancement). The motion picture shows crawl motions introducing a scheme of a temporary leader that is similar to group behavior of birds or fish.

         CHOBIE(3robots)               CHOBIE(5robots)
【Literature】
Reconfigurable group robots adaptively transforming a mechanical structure- Crawl motion and adaptive transformation with new algorithms -(PDF)
閉じる
Remodeling of living systems
スナック菓子は,形が似ていても内部構造は多種多様です(図1).この構造が食感に影響を与えていることはもちろんですが,生地の材料特性も重要です.本研究では,スナック菓子のミクロレベルの材料特性を調べる方法(図2)を開発し,従来のマクロレベルのヤング率と比べて10〜100倍高い値であることを初めて明らかにしました.

【発表論文】
 Ren KADOWAKI, Norio INOU, Hitoshi KIMURA:
 Measurement of Microscopic Young's Modulus of Crispy Foods,
 International Proceedings of Chemical, Biological & Environmental Engineering,
 Vol.50, pp79-83(2013)
閉じる
Group behavior of animals
スナック菓子は,形が似ていても内部構造は多種多様です(図1).この構造が食感に影響を与えていることはもちろんですが,生地の材料特性も重要です.本研究では,スナック菓子のミクロレベルの材料特性を調べる方法(図2)を開発し,従来のマクロレベルのヤング率と比べて10〜100倍高い値であることを初めて明らかにしました.

【発表論文】
Ren KADOWAKI, Norio INOU, Hitoshi KIMURA:
Measurement of Microscopic Young's Modulus of Crispy Foods,
International Proceedings of Chemical, Biological & Environmental Engineering,
Vol.50, pp79-83(2013)
閉じる
Cooperative control of muscular activity
When we exercise our arms and legs, multiple muscular legs cooperatively work. We estimate muscular activities with an optimization function because it is very difficult to measure active state of the each muscle directly.

# Biomechanics of free climbing
Indoor free climbing is studied from a biomechanical engineering viewpoint. The two-dimensional human model is proposed for the first step of this study. The model is a chain of nine links that produces torques at the link joints to keep configuration of the model. The produced torques can be calculated as a static problem when the terminal force is given. We introduce an evaluation function related to muscular activity and optimize the function. The minimized value is correlated with order of sensory loads to keep postures in climbing.

Professor Inou comments on free climbing(16:28-17:43 Japanese).



(jstsciencechannel アスリート解体新書 (33)
スポーツクライミング 〜省エネで壁を制す〜)
【Literature】
Norio INOU, Yoshihiko OTAKI, Ken OKUNUKI, Michihiko KOSEKI and Hitoshi KIMURA: Biomechanics of Free Climbing(A mathematical model for evaluation of climbing posture), The Impact of Technology on Sports II, pp.671-676, 2007